Frictions Savers, a bad idea for rock?

I rappel from trees a lot. Mostly for top rope soloing access, but for other things too.
For this I use a friction saver which is then pulled from the bottom. I've always used a DIY option comprised of a sling, a pear 'biner and a maillon link. On the cusp of buying a purpose built one and it dawned on me that they must be unsafe in rocking settings. When the rope is pulled, the sling and its metal parts, come crashing down. Those metal parts will often land on rock. Doesn't this make the metal parts "dropped gear"? Worse still, repeatedly dropped gear as this happens several times per outing? The frition saver is common in the tree climbing world, but those people work in a less rocky setting. My understanding is that steel (e.g. a maillon) can definitely have micro cracks. Aluminium, in the form of a ring, may or may not get micro cracks. I can't find an defining data on micro cracks, but am starting to not like the idea of friction savers in rocky settings. What do you think? 

Throwball line tied to the end of the rope gives a controlled pull.

Kinda standard arboristic anchor. m.petzl.com/INT/en/Professi…

There are way cheaper options round there. Search thru arborists stores.

Anyhow I cannot figure out any reason to bring it to rock climbing.

I’d be concerned that the end of the rope with knot, webbing, quicklink and carabiner was bound to get frequently stuck in/on rock features on the way down. 

Microfractures are not a real concern for climbing gear. Agreed with Em that the falling anchor is likely to get stuck unless you're on really steep ground.

I wouldn't worry about microfractures, I think the worst that will happen is that the screw gate mechanism can get banged up and the gat won't work properly.

Clifftop scrambling while setting up and taking down TRS anchors is often very sketchy; I'm all for a setup which reduces the need for this.

If you've used this setup a lot and it doesn't get stuck while pulling, I say rock on!

Having used real friction savers trimming trees, there's a couple of issues:

Trees are round, rocks much less so. It's more likely to get stuck.

Purpose-built friction savers have two steel rings. It's easy to get out of the way of them around a tree, less so at a crag or multi-pitch. It would really hurt to get hit by one.

If you're looking to not leave something, and looking beyond the climbing world, check out the fiddle stick. It works much better, as only the rope has to pass around the anchor, and it hurts less to get hit by a piece of plastic.

Thanks for the replay. I can see that friction savers are not ideal at the crag.

I get that the friction saver is creating a double strand rappel, which is different than my suggestion, but why not use a Biner Block and just have a single strand fixed and then be able to pull the rope after? The hardware gets back to you before the rope starts to fall, too.

Matthew Jaggerswrote:

I get that the friction saver is creating a double strand rappel, which is different than my suggestion, but why not use a Biner Block and just have a single strand fixed and then be able to pull the rope after? The hardware gets back to you before the rope starts to fall, too.

I'm not sure if I correctly understand your suggestion. If you mean just a blocked rap around the tree, then you are pulling the rope around the tree, which is the scenario that the friction saver seeks to prevent. If you mean blocked rap + friction saver, then yeah, seems fine, just set up everything correctly so it will pull and not girth hitch itself around the tree.

Matthew Jaggerswrote:

I get that the friction saver is creating a double strand rappel, which is different than my suggestion, but why not use a Biner Block and just have a single strand fixed and then be able to pull the rope after? The hardware gets back to you before the rope starts to fall, too.

I believe I can see how this could work.
Example: The friction save is attached a tree. Small ring left, large ring right. The rope hangs through both rings at the rope's midpoint and both strands reach the ground. A standard rappel setup. A biner block is place just left of the small ring. Now, provided the small ring won't, in any way, fit through the large ring, I can now climb (toprope solo) on the right side. For retrieval, a retriever ball or knot is placed just right of the large ring and must be sized to be able to pass through the large ring, but not the small one. Once done climbing, I can rappel double or single strand, then pull left and all the metal gear will be down, in a controlled way, before the rest of the rope falls. My gear is saved from possible micro cracks and my head too.

Before I test this, does anyone know if a Petzl Ring Small will pass through a Petzl Ring Large? Would the rings beign pulled together weight them in a strange way so as to cause them to crack? My guess is no as they pretty well rounded (being rings and all) and the forces in TRS shouldn't exceed 2kN? at a guess.

Using a throw line to control the drop is also an option, possibly the easiest of all. Something like this:
https://youtu.be/VwHKLNIjJx0?t=234

Noel Zwrote:

I believe I can see how this could work.
Example: The friction save is attached a tree. Small ring left, large ring right. The rope hangs through both rings at the rope's midpoint and both strands reach the ground. A standard rappel setup. A biner block is place just left of the small ring. Now, provided the small ring won't, in any way, fit through the large ring, I can now climb (toprope solo) on the right side. For retrieval, a retriever ball or knot is placed just right of the large ring and must be sized to be able to pass through the large ring, but not the small one. Once done climbing, I can rappel double or single strand, then pull left and all the metal gear will be down, in a controlled way, before the rest of the rope falls. My gear is saved from possible micro cracks and my head too.

Before I test this, does anyone know if a Petzl Ring Small will pass through a Petzl Ring Large? Would the rings beign pulled together weight them in a strange way so as to cause them to crack? My guess is no as they pretty well rounded (being rings and all) and the forces in TRS shouldn't exceed 2kN? at a guess.

Noel this won't work. The large ring will pull the rope around the tree 

The small ring won’t pass through the large.  Once the rings are together there shouldn’t be any way they could separate and clank when they come back together.  The knot will pull the small ring next to the large and they stay together while loaded.

Brockywrote:

The small ring won’t pass through the large.  Once the rings are together there shouldn’t be any way they could separate and clank when they come back together.  The knot will pull the small ring next to the large and they stay together while loaded.

So what I plan on testing should work. 

Yes, just make sure the knot, small ball, or a smaller steel ring from hardware store, passes through the big ring but can’t go through the small one.  Ring is the most trustworthy, can’t squeeze through no matter how hard you pull.